Planing cutter



July 24, 1928.

Filed J n. 27, 1925 Bag! In yen for Johcysaarfifftonders .fit'tornefPatented July 24, 1928.

UNITED STATES.

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a lication filed Jairua'ry 27, 1925, serial-no. 5,121; and in SwedenFebruary 7, 1924.

Heretofore, planing cutters of a great width, that is to say of greatextension in the axial direction, and provided with continuous cuttingedges, have suffered from a number of great disadvantages. In themanufacture of such cutters great difficulties are met with in temperingand grinding the wide cutting edges, or in otherwise preparing the same,without flaws setting in in the material, and a matter of still greaterimportance is, that if the cutting edge is injured in any place duringwork, for instance, by hitting a nail, generally the whole cutting edgewill become unfit for work, which, naturally is a circumstance of greatimportance from the point of view of cost.

For this reason the cutting edge has been divided. into sections alongthe width thereof, that is to say, along the axis of the cutter. If insuch a section the cutting edge is injured, the section having theinjured edge may be easily replaced by a new one, and thus the wholeplaning cutter need not be discarded. I

In a cutter divided in the manner set forth, however, the rigidconnection between the sections will be a matter of the utmostimportance, a safeguard having to be provided against any one of thesections separating from the others, in case it happens to burst duringwork or is otherwise injured. The object of the present invention is toprovide such mutual connection between the sections that they may,practically, be regarded as a continuouswhole piece, while excludingevery possibility of any one of the sections separating from the others,if the sections are not deliberately taken apart.

This is secured, according to the invention, by the arrangement oflocking means between the sections, which locking means embrace or gripthe sections in such a manner that the parts of asection that may haveburst cannot separate under the action of the centrifugal force. Thelocking parts should preferably be made of a tougher material than thesections proper. Between the latter, therefore, special locking rings ofsuch tougher material are preferably pro vided, the said locking ringshaving such a cross section that the rings, co-operating with thecorrespondingly shaped-end profiles of the sections, are caused to lockthe sections onto each other by pressure in a radial direction, when thesaid locking rings and the sections are pressed together axially.

In the accompanying drawing, an embodiment of the invention isillustrated by way of example. Fig. 1 is an elevation of the cutter, theone half thereof being shown in longitudinal section. Fig. 2 shows oneof the cutter sections viewed in the axial direction, and Fig. 3 showsthe same section viewed from the side and in the axial direction.

In the embodiment illustrated, the planing cutter is divided into threeannular sections 1 each section comprising a hub portion and a pluralityof blade portions, the blade portions being of greater width than theremainder of the section and being adapted to be aligned with each otherwhen the cutter is assembled to form substantially continuous blades, asshown in Fig. 1. The

sections 1 are slidonto the cutter spindle 2,

and between each pair of sections there is slid onto the spindle alocking ring 3 which,

in the case illustrated, is of a nearly trapezoidal, inwardly taperingcross section. The end portions of the cutting sections 1 are shapedcorrespondingly, in aconical fashion, and will thus be embraced orgripped by the rings 3, which securely prevent separation of the partsof a section that may have burst. Outside the outer ends of the twoextreme sections there are also provided similar rings 4:, one of whichbears against a boss 5 on the spindle 2, while the other bears againstthe nut 6 which is screwed onto the threaded end portion of the spindle2 and serves to force the whole structure together. To secure rigidengagement between the sections 1 and the locking rings 3 and 4, thecontact surfaces of the parts may be grooved, as shown in the drawing.

As already set forth hereinbefore, the surfaces of the locking meansco-operating with each other may be of any suitable outline effectingthe locking aimed at. For instance, the said outline may be step-like orwavy. However, the outline shown in the drawing is preferred from apractical point of view, and the conical shape may, as shown to theextreme left of the drawing,

be altered into a slight spherical shape.

\Vhat I claim as new and desire to secure by Letters Patent of theUnited States of America is A rotary planing cutter comprising aplurality of annular sections mounted on a shaft, the adjacent surfacesof said sections being recessed to form inwardly tapering annular spacesof approximately trapezoidal cross section between the sections, annularlocking members fitting in said spaces and'having surfaces engaging saidadjacent surfaces of the sections, the surfaces of said locking membersbeing roughened to enable the locking members to securely grip said 1adjacent surfaces, each of said sections being provided withlongitudinally extending blade portions of greater width than theremainder of the section, the blade portions of the several sectionsbeing adapted to be aligned with each other when the cutter isassembled, to form substantially continuous cutting blades, and meansexerting axial pressure on said sections.

In testimony whereof I aflix my signature.

J OHAN OSCAR LIFFLANDEB.

